What is a hormone? multiple choice: o a chemical released from a nerve cell that affects nearby cells across a synapse o a chemical released from an endocrine gland that affects target cells without entering the bloodstream o a chemical found in the blood that catalyzes the destruction of ingested toxins and foreign substances o a chemical excreted from sweat gland that signals other individuals about the physiological status of the body o a chemical regulator secreted from an endocrine gland that travels through the bloodstream to affect target cells

Salmonella typhimurium is a food-borne bacterial pathogen that can cause severe gastrointestinal disease. salmonella is often phagocytosed by macrophages that normally destroy bacterial pathogens, but this bacterium is somehow able to prevent the complete maturation of phagolysosomes. salmonella is able to tolerate the low ph of phagolysosomes, and in fact responds to the drop in ph by secreting toxins that interfere with other cellular responses. which of the following differences would you expect to contribute to the survival of a bacterium within an salmonella-containing phagosome, compared to a healthy phagolysosome? decreased activity of acid hydrolases increased activity of acid hydrolases decreased import of h+ ions increased import of h+ ions my guess is decreased activity of acid hydrolases but i'm not sure.

Which would be an adaptation in a rainforest, but not in a tundra? a. ability to store water for a long time b. fur that blends in with snow c. strong claws for killing prey d. a beak that can dig into thick trees

Ais a landform that is formed at the mouth of a river from the deposition of sediment carried by the river as the water flows.